私と同じ or 私のと同じ when comparing possession

Question

This question made me think.

彼の車は私と同じです。
His car is the same as mine.

Except that isn't a literal translation. A literal translation would be "His car is the same as me". But I am not a car.

Would it be incorrect to add a の into this sentence i.e.:

彼の車は私のと同じです。

A Google search for "私のと同じ" does not result in many convincing hits so I'm assuming it's wrong.

Can we understand this grammatically? Is the の just assumed to be redundant? ...

Answer 1

In Japanese, 彼の車は私と同じです is a perfectly natural sentence. When you compare two things, this type of omission^* is extremely common in Japanese, and it can be found even in the most formal writings.

^{(* This may seem to be "omission" from the English perspective, but Japanese people may say nothing is omitted.)}

Examples:

• 彼の英語は私より上手です。
  His English is better than mine.

• 地球の体積は月より大きい。
  The volume of the earth is larger than that of the moon.

• この店で売られているリンゴはあの店より美味しい。
  Apples sold at this store are more delicious than those sold at that store.

• 彼の考えは君とは違う。
  His opinion is different from yours.

• 限定版の値段は通常版と同じです。
  The price of the limited edition is the same as that of the regular edition.

(Actually "His car is the same as me" is a common mistake made by Japanese students.)

If there were not many examples of 私のと同じ, it's probably because 私の is relatively colloquial, and in speech の tends to be "omitted" anyway. Instead of の, you can use the stiffer pronoun (の)それ and say the following:

• 彼の車は私の車と同じです。
  彼の車は私のそれと同じです。
• 地球の体積は月の体積より大きい。
  地球の体積は月のそれより大きい。

But sentences like these are found mainly in strict technical documents or translated materials. You can (or should) stick to the shorter versions in most cases.

EDIT: Of course you have to avoid "omission" when it causes confusion:

• 君のお父さんは僕のお父さんより背が高い。
  Your father is taller than my father.
• 君のお父さんは僕より背が高い。
  Your father is taller than me.